The invention relates to a method and device for forming shaped fibrous articles or the like, especially of tampons. In particular, it relates to ultrasonic shaping of fibrous articles.
Fibrous articles, for example, tampons, ear plugs or the like, are formed having a specific shape. Moreover, these fibrous products can be formed of a single type of fiber or of mixed fibers (natural or synthetic). These fibrous products are brought to the desired shape either by rolling or by applying a shaping tool. Thus, for example, a shaping tool having a recess is applied to the tip of a tampon, the recess having the shape to be imparted to the tampon tip. An example of this is shown in Brien et al., U.S. Pat. No. 3,738,364.
An additional prior art shape-forming apparatus is illustrated in FIG. 3. In a conventional shaping device, a tampon 1 having an essentially circular cross-section is held in a guide-holder 2. By means of this guide-holder 2, the tip 3 of the tampon 1 projects beyond the guide-holder 2 and is introduced into a recess 4 of a heated shaping tool 5. The recess 4 has the shape of the desired tampon tip to be produced. The tampon 1 is introduced under pressure into this recess 4, with the result that the fibers in the tip region are compacted. on account of the continuously decreasing cross-section, the friction of the tampon fibers on the surface of the recess 4 increases and the individual tampon fibers are compressed in the tip region, so that the internal friction also rises sharply. It has been shown that the outermost tampon tip is shaped only insufficiently or, as shown in FIG. 3, not at all.